LiftMaster MJ5011 medium duty logic jackshaft operator for high or vertical lift sectional doors or small rolling doors and grilles. It has a high starting torque motor with overload protection and an adjustable friction clutch. The MJ5011 has a medium-duty programmable integrated circuit board and a built-in 315MHz receiver. Comes with a push button station with 3 buttons, for open/close/stop functions. All operators are factory preset to C2 mode, providing momentary contact to open and stop, with constant contact to close. Monitored entrapment protection, using approved photo sensors or sensing edges, is optional, although recommended, when using this wiring type. Momentary contact to close (B2 mode) is an available optional wiring type, but can only be selected when the appropriate monitored entrapment protection device, either LiftMaster CPS-U / CPS-UN4 photo sensors or a monitored 4-wire sensing edge (via the CPS-EI interface), is present. The Medium-Duty Logic operator is pre-wired to accept CPS-U / CPS-UN4 / CPS-EI monitored entrapment protection devices.